I have been in contact with Keir, they inform me they are using the codes issued to them in March by HMRC.
Before contacting Keir please check on your recent pension advice that Keir are using the same code that your were notified by HMRC.
To obtain your code you can contact HMRC direct on 0300 200 3300 using your unique reference from your pension advice should start 507/*******.
If HMRC tax code is different to the one on your pension advice request that HMRC notify Keir of the correct coding and an adjustment will be made on next months pension
If you were notified by electronic means of your Code you will need to log onto the government gateway with your own unique reference.
Please do not contact Keir direct they cannot make any adjustment they have to wait notification from HMRC before any adjustment is made.